Inbred maize line PH03D

ABSTRACT

An inbred maize line, designated PH03D, the plants and seeds of inbred maize line PH03D, methods for producing a maize plant produced by crossing the inbred line PH03D with itself or with another maize plant, and hybrid maize seeds and plants produced by crossing the inbred line PH03D with another maize line or plant.

FIELD OF THE INVENTION

This invention is in the field of maize breeding, specifically relating to an inbred maize line designated PH03D.

BACKGROUND OF THE INVENTION

The goal of plant breeding is to combine in a single variety or hybrid various desirable traits. For field crops, these traits may include resistance to diseases and insects, tolerance to heat and drought, reducing the time to crop maturity, greater yield, and better agronomic quality. With mechanical harvesting of many crops, uniformity of plant characteristics such as germination and stand establishment, growth rate, maturity, and plant and ear height, is important.

Field crops are bred through techniques that take advantage of the plant's method of pollination. A plant is self-pollinated if pollen from one flower is transferred to the same or another flower of the same plant. A plant is cross-pollinated if the pollen comes from a flower on a different plant.

Plants that have been self-pollinated and selected for type for many generations become homozygous at almost all gene loci and produce a uniform population of true breeding progeny. A cross between two different homozygous lines produces a uniform population of hybrid plants that may be heterozygous for many gene loci. A cross of two plants each heterozygous at a number of gene loci will produce a population of hybrid plants that differ genetically and will not be uniform.

Maize (zea mays L.), often referred to as corn in the United States, can be bred by both self-pollination and cross-pollination techniques. Maize has separate male and female flowers on the same plant, located on the tassel and the ear, respectively. Natural pollination occurs in maize when wind blows pollen from the tassels to the silks that protrude from the tops of the ears.

A reliable method of controlling male fertility in plants offers the opportunity for improved plant breeding. This is especially true for development of maize hybrids, which relies upon some sort of male sterility system. There are several options for controlling male fertility available to breeders, such as: manual or mechanical emasculation (or detasseling), cytoplasmic male sterility, genetic male sterility, gametocides and the like.

Hybrid maize seed is typically produced by a male sterility system incorporating manual or mechanical detasseling. Alternate strips of two maize inbreds are planted in a field, and the pollen-bearing tassels are removed from one of the inbreds (female). Providing that there is sufficient isolation from sources of foreign maize pollen, the ears of the detasseled inbred will be fertilized only from the other inbred (male), and the resulting seed is therefore hybrid and will form hybrid plants.

The laborious, and occasionally unreliable, detasseling process can be avoided by using cytoplasmic male-sterile (CMS) inbreds. Plants of a CMS inbred are male sterile as a result of factors resulting from the cytoplasmic, as opposed to the nuclear, genome. Thus, this characteristic is inherited exclusively through the female parent in maize plants, since only the female provides cytoplasm to the fertilized seed. CMS plants are fertilized with pollen from another inbred that is not male-sterile. Pollen from the second inbred may or may not contribute genes that make the hybrid plants male-fertile. Seed from detasseled fertile maize and CMS produced seed of the same hybrid can be blended to insure that adequate pollen loads are available for fertilization when the hybrid plants are grown.

There are several methods of conferring genetic male sterility available, such as multiple mutant genes at separate locations within the genome that confer male sterility, as disclosed in U.S. Pat. Nos. 4,654,465 and 4,727,219 to Brar et al. and chromosomal translocations as described by Patterson in U.S. Pat. Nos. 3,861,709 and 3,710,511. These and all patents referred to are incorporated by reference. In addition to these methods, Albertsen et al., of Pioneer Hi-Bred, U.S. patent application Ser. No. 07/848,433, have developed a system of nuclear male sterility which includes: identifying a gene which is critical to male fertility; silencing this native gene which is critical to male fertility; removing the native promoter from the essential male fertility gene and replacing it with an inducible promoter; inserting this genetically engineered gene back into the plant; and thus creating a plant that is male sterile because the inducible promoter is not "on" resulting in the male fertility gene not being transcribed. Fertility is restored by inducing, or turning "on", the promoter, which in turn allows the gene that confers male fertility to be transcribed.

There are many other methods of conferring genetic male sterility in the art, each with its own benefits and drawbacks. These methods use a variety of approaches such as delivering into the plant a gene encoding a cytotoxic substance associated with a male tissue specific promoter or an antisense system in which a gene critical to fertility is identified and an antisense to that gene is inserted in the plant (see: Fabinjanski, et al. EPO 89/3010153.8 publication no. 329,308 and PCT application PCT/CA90/00037 published as WO 90/08828).

Another system useful in controlling male sterility makes use of gametocides. Gametocides are not a genetic system, but rather a topical application of chemicals. These chemicals affect cells that are critical to male fertility. The application of these chemicals affects fertility in the plants only for the growing season in which the gametocide is applied (see Carlson, Glenn R., U.S. Pat. No. 4,936,904). Application of the gametocide, timing of the application and genotype specificity often limit the usefulness of the approach.

The use of male sterile inbreds is but one factor in the production of maize hybrids. The development of maize hybrids requires, in general, the development of homozygous inbred lines, the crossing of these lines, and the evaluation of the crosses. Pedigree breeding and recurrent selection breeding methods are used to develop inbred lines from breeding populations. Breeding programs combine the genetic backgrounds from two or more inbred lines or various other germplasm sources into breeding pools from which new inbred lines are developed by selfing and selection of desired phenotypes. The new inbreds are crossed with other inbred lines and the hybrids from these crosses are evaluated to determine which of those have commercial potential. Plant breeding and hybrid development are expensive and time consuming processes.

Pedigree breeding starts with the crossing of two genotypes, each of which may have one or more desirable characteristics that is lacking in the other or which complements the other. If the two original parents do not provide all the desired characteristics, other sources can be included in the breeding population. In the pedigree method, superior plants are selfed and selected in successive generations. In the succeeding generations the heterozygous condition gives way to homogeneous lines as a result of self-pollination and selection. Typically in the pedigree method of breeding five or more generations of selfing and selection is practiced: F₁ →F₂ ; F₃ →F₄ ; F₄ →F₅, etc.

Recurrent selection breeding, backcrossing for example, can be used to improve an inbred line. Backcrossing can be used to transfer a specific desirable trait from one inbred or source to an inbred that lacks that trait. This can be accomplished, for example, by first crossing a superior inbred (recurrent parent) to a donor inbred (non-recurrent parent), that carries the appropriate gene(s) for the trait in question. The progeny of this cross is then mated back to the superior recurrent parent followed by selection in the resultant progeny for the desired trait to be transferred from the non-recurrent parent. After five or more backcross generations with selection for the desired trait, the progeny will be heterozygous for loci controlling the characteristic being transferred, but will be like the superior parent for most or almost all other genes. The last backcross generation is then selfed to give pure breeding progeny for the gene(s) being transferred.

A single cross maize hybrid results from the cross of two inbred lines, each of which has a genotype that complements the genotype of the other. The hybrid progeny of the first generation is designated F₁. In the development of commercial hybrids only the F₁ hybrid plants are sought. Preferred F₁ hybrids are more vigorous than their inbred parents. This hybrid vigor, or heterosis, can be manifested in many polygenic traits, including increased vegetative growth and increased yield.

The development of a maize hybrid involves three steps: (1) the selection of plants from various germplasm pools for initial breeding crosses; (2) the selfing of the selected plants from the breeding crosses for several generations to produce a series of inbred lines, which, although different from each other, breed true and are highly uniform; and (3) crossing the selected inbred lines with different inbred lines to produce the hybrid progeny (F₁). During the inbreeding process in maize, the vigor of the lines decreases. Vigor is restored when two different inbred lines are crossed to produce the hybrid progeny (F₁). An important consequence of the homozygosity and homogeneity of the inbred lines is that the hybrid between a defined pair of inbreds will always be the same. Once the inbreds that give a superior hybrid have been identified, the hybrid seed can be reproduced indefinitely as long as the homogeneity of the inbred parents is maintained.

A single cross hybrid is produced when two inbred lines are crossed to produce the F₁ progeny. A double cross hybrid is produced from four inbred lines crossed in pairs (A×B and C×D) and then the two F₁ hybrids are crossed again (A×B)×(C×D). Much of the hybrid vigor exhibited by F₁ hybrids is lost in the next generation (F₂). Consequently, seed from hybrids is not used for planting stock.

Hybrid seed production requires elimination or inactivation of pollen produced by the female parent. Incomplete removal or inactivation of the pollen provides the potential for self pollination. This inadvertently self pollinated seed may be unintentionally harvested and packaged with hybrid seed.

Once the seed is planted, it is possible to identify and select these self pollinated plants. These self pollinated plants will be genetically equivalent to the female inbred line used to produce the hybrid.

Typically these self pollinated plants can be identified and selected due to their decreased vigor. Female selfs are identified by their less vigorous appearance for vegetative and/or reproductive characteristics, including shorter plant height, small ear size, ear and kernel shape, cob color, or other characteristics.

Identification of these self pollinated lines can also be accomplished through molecular marker analyses. See, "The Identification of Female Selfs in Hybrid Maize: A Comparison Using Electrophoresis and Morphology", Smith, J. S. C. and Wych, R. D., Seed Science and Technology 14, pp. 1-8 (1995), the disclosure of which is expressly incorporated herein by reference. Through these technologies, the homozygosity of the self pollinated line can be verified by analyzing allelic composition at various loci along the genome. Those methods allow for rapid identification of the invention disclosed herein. See also, "Identification of Atypical Plants in Hybrid Maize Seed by Postcontrol and Electrophoresis" Sarca, V. et al., Probleme de Genetica Teoritica si Aplicata Vol. 20 (1) p. 29-42.

As is readily apparent to one skilled in the art, the foregoing are only two of the various ways by which the inbred can be obtained by those looking to use the germplasm. Other means are available, and the above examples are illustrative only.

Maize is an important and valuable field crop. Thus, a continuing goal of plant breeders is to develop high-yielding maize hybrids that are agronomically sound based on stable inbred lines. The reasons for this goal are obvious: to maximize the amount of grain produced with the inputs used and minimize susceptibility of the crop to pests and environmental stresses. To accomplish this goal, the maize breeder must select and develop superior inbred parental lines for producing hybrids. This requires identification and selection of genetically unique individuals that occur in a segregating population. The segregating population is the result of a combination of crossover events plus the independent assortment of specific combinations of alleles at many gene loci that results in specific genotypes. The probability of selecting any one individual with a specific genotype from a breeding cross is infinitesimal due to the large number of segregating genes and the unlimited recombinations of these genes, some of which may be closely linked. However, the genetic variation among individual progeny of a breeding cross allows for the identification of rare and valuable new genotypes. These new genotypes are neither predictable nor incremental in value, but rather the result of manifested genetic variation combined with selection methods, environments and the actions of the breeder.

Thus, even if the entire genotypes of the parents of the breeding cross were characterized and a desired genotype known, only a few, if any, individuals having the desired genotype may be found in a large segregating F₂ population. Typically, however, neither the genotypes of the breeding cross parents nor the desired genotype to be selected is known in any detail. In addition, it is not known how the desired genotype would react with the environment. This genotype by environment interaction is an important, yet unpredictable, factor in plant breeding. A breeder of ordinary skill in the art cannot predict the genotype, how that genotype will interact with various climatic conditions or the resulting phenotypes of the developing lines, except perhaps in a very broad and general fashion. A breeder of ordinary skill in the art would also be unable to recreate the same line twice from the very same original parents as the breeder is unable to direct how the genomes combine or how they will interact with the environmental conditions. This unpredictability results in the expenditure of large amounts of research resources in the development of a superior new maize inbred line.

SUMMARY OF THE INVENTION

According to the invention, there is provided a novel inbred maize line, designated PH03D. This invention thus relates to the seeds of inbred maize line PH03D, to the plants of inbred maize line PH03D, and to methods for producing a maize plant produced by crossing the inbred line PH03D with itself or another maize line. This invention further relates to hybrid maize seeds and plants produced by crossing the inbred line PH03D with another maize line.

Definitions

In the description and examples that follow, a number of terms are used herein. In order to provide a clear and consistent understanding of the specification and claims, including the scope to be given such terms, the following definitions are provided. NOTE: ABS is in absolute terms and %MN is percent of the mean for the experiments in which the inbred or hybrid was grown. These designators will follow the descriptors to denote how the values are to be interpreted. Below are the descriptors used in the data tables included herein.

ANT ROT=ANTHRACNOSE STALK ROT (Colletotrichum graminicola). A 1 to 9 visual rating indicating the resistance to Anthracnose Stalk Rot. A higher score indicates a higher resistance.

BAR PLT=BARREN PLANTS. The percent of plants per plot that were not barren (lack ears).

BRT STK=BRITTLE STALKS. This is a measure of the stalk breakage near the time of pollination, and is an indication of whether a hybrid or inbred would snap or break near the time of flowering under severe winds. Data are presented as percentage of plants that did not snap.

BU ACR=YIELD (BUSHELS/ACRE). Yield of the grain at harvest in bushels per acre adjusted to 15.5% moisture.

CLD TST=COLD TEST. The percent of plants that germinate under cold test conditions.

CLN=CORN LETHAL NECROSIS. Synergistic interaction of maize chlorotic mottle virus (MCMV) in combination with either maize dwarf mosaic virus (MDMV-A or MDMV-B) or wheat streak mosaic virus (WSMV). A 1 to 9 visual rating indicating the resistance to Corn Lethal Necrosis. A higher score indicates a higher resistance.

COM RST=COMMON RUST (Puccinia sorghi). A 1 to 9 visual rating indicating the resistance to Common Rust. A higher score indicates a higher resistance.

D/D=DRYDOWN. This represents the relative rate at which a hybrid will reach acceptable harvest moisture compared to other hybrids on a 1-9 rating scale. A high score indicates a hybrid that dries relatively fast while a low score indicates a hybrid that dries slowly.

DIP ERS=DIPLODIA EAR MOLD SCORES (Diplodia maydis and Diplodia macrospora). A 1 to 9 visual rating indicating the resistance to Diplodia Ear Mold. A higher score indicates a higher resistance.

DRP EAR=DROPPED EARS. A measure of the number of dropped ears per plot and represents the percentage of plants that did not drop ears prior to harvest.

D/T=DROUGHT TOLERANCE. This represents a 1-9 rating for drought tolerance, and is based on data obtained under stress conditions. A high score indicates good drought tolerance and a low score indicates poor drought tolerance.

EAR HT=EAR HEIGHT. The ear height is a measure from the ground to the highest placed developed ear node attachment and is measured in inches.

EAR MLD=General Ear Mold. Visual rating (1-9 score) where a "1" is very susceptible and a "9" is very resistant. This is based on overall rating for ear mold of mature ears without determining the specific mold organism, and may not be predictive for a specific ear mold.

EAR SZ=EAR SIZE. A 1 to 9 visual rating of ear size. The higher the rating the larger the ear size.

ECB 1LF=EUROPEAN CORN BORER FIRST GENERATION LEAF FEEDING (Ostrinia nubilalis). A 1 to 9 visual rating indicating the resistance to preflowering leaf feeding by first generation European Corn Borer. A higher score indicates a higher resistance.

ECB 21T=EUROPEAN CORN BORER SECOND GENERATION INCHES OF TUNNELING (Ostrinia nubilalis). Average inches of tunneling per plant in the stalk.

ECB 2SC=EUROPEAN CORN BORER SECOND GENERATION (Ostrinia nubilalis). A 1 to 9 visual rating indicating post flowering degree of stalk breakage and other evidence of feeding by European Corn Borer, Second Generation. A higher score indicates a higher resistance.

ECB DPE=EUROPEAN CORN BORER DROPPED EARS (Ostrinia nubilalis). Dropped ears due to European Corn Borer. Percentage of plants that did not drop ears under second generation corn borer infestation.

EST CNT=EARLY STAND COUNT. This is a measure of the stand establishment in the spring and represents the number of plants that emerge on per plot basis for the inbred or hybrid.

EYE SPT=Eye Spot (Kabatiella zeae or Aureobasidium zeae). A 1 to 9 visual rating indicating the resistance to Eye Spot. A higher score indicates a higher resistance.

FUS ERS=FUSARIUM EAR ROT SCORE (Fusarium moniliforme or Fusarium subglutinans). A 1 to 9 visual rating indicating the resistance to Fusarium ear rot. A higher score indicates a higher resistance.

GDU=Growing Degree Units. Using the Barger Heat Unit Theory, which assumes that maize growth occurs in the temperature range 50° F.-86° F. and that temperatures outside this range slow down growth; the maximum daily heat unit accumulation is 36 and the minimum daily heat unit accumulation is 0. The seasonal accumulation of GDU is a major factor in determining maturity zones.

GDU SHD=GDU TO SHED. The number of growing degree units (GDUs) or heat units required for an inbred line or hybrid to have approximately 50 percent of the plants shedding pollen and is measured from the time of planting. Growing degree units are calculated by the Barger Method, where the heat units for a 24-hour period are: ##EQU1##

The highest maximum temperature used is 86° F. and the lowest minimum temperature used is 50° F. For each inbred or hybrid it takes a certain number of GDUs to reach various stages of plant development.

GDU SLK=GDU TO SILK. The number of growing degree units required for an inbred line or hybrid to have approximately 50 percent of the plants with silk emergence from time of planting. Growing degree units are calculated by the Barger Method as given in GDU SHD definition.

GIB ERS=GIBBERELLA EAR ROT (PINK MOLD) (Gibberella zeae). A 1 to 9 visual rating indicating the resistance to Gibberella Ear Rot. A higher score indicates a higher resistance.

GLF SPT=Gray Leaf Spot (Cercospora zeae-maydis). A 1 to 9 visual rating indicating the resistance to Gray Leaf Spot. A higher score indicates a higher resistance.

GOS WLT=Goss' Wilt (Corynebacterium nebraskense). A 1 to 9 visual rating indicating the resistance to Goss' Wilt. A higher score indicates a higher resistance.

GRN APP=GRAIN APPEARANCE. This is a 1 to 9 rating for the general appearance of the shelled grain as it is harvested based on such factors as the color of harvested grain, any mold on the grain, and any cracked grain. High scores indicate good grain quality.

H/POP=YIELD AT HIGH DENSITY. Yield ability at relatively high plant densities on 1-9 relative rating system with a higher number indicating the hybrid responds well to high plant densities for yield relative to other hybrids. A 1, 5, and 9 would represent very poor, average, and very good yield response, respectively, to increased plant density.

HC BLT=HELMINTHOSPORIUM CARBONUM LEAF BLIGHT (Helminthosporium carbonum). A 1 to 9 visual rating indicating the resistance to Helminthosporium infection. A higher score indicates a higher resistance.

HD SMT=HEAD SMUT (Sphacelotheca reiliana). This score indicates the percentage of plants not infected.

INC D/A=GROSS INCOME (DOLLARS PER ACRE). Relative income per acre assuming drying costs of two cents per point above 15.5 percent harvest moisture and current market price per bushel.

INCOME/ACRE. Income advantage of hybrid to be patented over other hybrid on per acre basis.

INC ADV=GROSS INCOME ADVANTAGE. GROSS INCOME advantage of variety #1 over variety #2.

KSZ DCD=KERNEL SIZE DISCARD. The percent of discard seed; calculated as the sum of discarded tip kernels and extra large kernels.

L/POP=YIELD AT LOW DENSITY. Yield ability at relatively low plant densities on a 1-9 relative system with a higher number indicating the hybrid responds well to low plant densities for yield relative to other hybrids. A 1, 5, and 9 would represent very poor, average, and very good yield response, respectively, to low plant density.

MDM CPX=MAIZE DWARF MOSAIC COMPLEX (MDMV=Maize Dwarf Mosaic Virus and MCDV=Maize Chlorotic Dwarf Virus). A 1 to 9 visual rating indicating the resistance to Maize Dwarf Mosaic Complex. A higher score indicates a higher resistance.

MST=HARVEST MOISTURE. The moisture is the actual percentage moisture of the grain at harvest.

MST ADV=MOISTURE ADVANTAGE. The moisture advantage of variety #1 over variety #2 as calculated by: MOISTURE of variety #2-MOISTURE of variety #1=MOISTURE ADVANTAGE of variety #1.

NLF BLT=Northern Leaf Blight (Helminthosporium turcicum or Exserohilum turcicum). A 1 to 9 visual rating indicating the resistance to Northern Leaf Blight. A higher score indicates a higher resistance.

PLT HT=PLANT HEIGHT. This is a measure of the height of the plant from the ground to the tip of the tassel in inches.

POL SC=POLLEN SCORE. A 1 to 9 visual rating indicating the amount of pollen shed. The higher the score the more pollen shed.

POL WT=POLLEN WEIGHT. This is calculated by dry weight of tassels collected as shedding commences minus dry weight from similar tassels harvested after shedding is complete.

It should be understood that the inbred can, through routine manipulation of cytoplasmic or other factors, be produced in a male-sterile form. Such embodiments are also contemplated within the scope of the present claims.

POP K/A=PLANT POPULATIONS. Measured as 1000s per acre.

POP ADV=PLANT POPULATION ADVANTAGE. The plant population advantage of variety #1 over variety #2 as calculated by PLANT POPULATION of variety #2-PLANT POPULATION of variety #1=PLANT POPULATION ADVANTAGE of variety #1.

PRM=PREDICTED RELATIVE MATURITY. This trait, predicted relative maturity, is based on the harvest moisture of the grain. The relative maturity rating is based on a known set of checks and utilizes standard linear regression analyses and is also referred to as the Comparative Relative Maturity Rating System that is similar to the Minnesota Relative Maturity Rating System.

PRM SHD=A relative measure of the growing degree units (GDU) required to reach 50% pollen shed. Relative values are predicted values from the linear regression of observed GDU's on relative maturity of commercial checks.

RT LDG=ROOT LODGING. Root lodging is the percentage of plants that do not root lodge; plants that lean from the vertical axis at an approximately 30° angle or greater would be counted as root lodged.

RTL ADV=ROOT LODGING ADVANTAGE. The root lodging advantage of variety #1 over variety #2.

SCT GRN=SCATTER GRAIN. A 1 to 9 visual rating indicating the amount of scatter grain (lack of pollination or kernel abortion) on the ear. The higher the score the less scatter grain.

SDG VGR=SEEDLING VIGOR. This is the visual rating (1 to 9) of the amount of vegetative growth after emergence at the seedling stage (approximately five leaves). A higher score indicates better vigor.

SEL IND=SELECTION INDEX. The selection index gives a single measure of the hybrid's worth based on information for up to five traits. A maize breeder may utilize his or her own set of traits for the selection index. One of the traits that is almost always included is yield. The selection index data presented in the tables represent the mean value averaged across testing stations.

SLF BLT=SOUTHERN LEAF BLIGHT (Helminthosporium maydis or Bipolaris maydis). A 1 to 9 visual rating indicating the resistance to Southern Leaf Blight. A higher score indicates a higher resistance.

SOU RST=SOUTHERN RUST (Puccinia polysora). A 1 to 9 visual rating indicating the resistance to Southern Rust. A higher score indicates a higher resistance.

STA GRN=STAY GREEN. Stay green is the measure of plant health near the time of black layer formation (physiological maturity). A high score indicates better late-season plant health.

STD ADV=STALK STANDING ADVANTAGE. The advantage of variety #1 over variety #2 for the trait STK CNT.

STK CNT=NUMBER OF PLANTS. This is the final stand or number of plants per plot.

STK LDG=STALK LODGING. This is the percentage of plants that did not stalk lodge (stalk breakage) as measured by either natural lodging or pushing the stalks and determining the percentage of plants that break below the ear.

STW WLT=Stewart's Wilt (Erwinia stewartii). A 1 to 9 visual rating indicating the resistance to Stewart's Wilt. A higher score indicates a higher resistance.

TAS BLS=TASSEL BLAST. A 1 to 9 visual rating was used to measure the degree of blasting (necrosis due to heat stress) of the tassel at the time of flowering. A 1 would indicate a very high level of blasting at time of flowering, while a 9 would have no tassel blasting.

TAS SZ=TASSEL SIZE. A 1 to 9 visual rating was used to indicate the relative size of the tassel. The higher the rating the larger the tassel.

TAS WT=TASSEL WEIGHT. This is the average weight of a tassel (grams) just prior to pollen shed.

TEX EAR=EAR TEXTURE. A 1 to 9 visual rating was used to indicate the relative hardness (smoothness of crown) of mature grain. A 1 would be very soft (extreme dent) while a 9 would be very hard (flinty or very smooth crown).

TILLER=TILLERS. A count of the number of tillers per plot that could possibly shed pollen was taken. Data are given as a percentage of tillers: number of tillers per plot divided by number of plants per plot.

TST WT=TEST WEIGHT (UNADJUSTED). The measure of the weight of the grain in pounds for a given volume (bushel).

TST WTA=TEST WEIGHT ADJUSTED. The measure of the weight of the grain in pounds for a given volume (bushel) adjusted for 15.5 percent moisture.

TSW ADV=TEST WEIGHT ADVANTAGE. The test weight advantage of variety #1 over variety #2.

WIN M %=PERCENT MOISTURE WINS.

WIN Y %=PERCENT YIELD WINS.

YLD=YIELD. It is the same as BU ACR ABS.

YLD ADV=YIELD ADVANTAGE. The yield advantage of variety #1 over variety #2 as calculated by: YIELD of variety #1-YIELD variety #2=yield advantage of variety #1.

YLD SC=YIELD SCORE. A 1 to 9 visual rating was used to give a relative rating for yield based on plot ear piles. The higher the rating the greater visual yield appearance.

DETAILED DESCRIPTION OF THE INVENTION

Inbred maize lines are typically developed for use in the production of hybrid maize lines. Inbred maize lines need to be highly homogeneous, homozygous and reproducible to be useful as parents of commercial hybrids. There are many analytical methods available to determine the homozygotic and phenotypic stability of these inbred lines.

The oldest and most traditional method of analysis is the observation of phenotypic traits. The data is usually collected in field experiments over the life of the maize plants to be examined. Phenotypic characteristics most often observed are for traits associated with plant morphology, ear and kernel morphology, insect and disease resistance, maturity, and yield.

In addition to phenotypic observations, the genotype of a plant can also be examined. There are many laboratory-based techniques available for the analysis, comparison and characterization of plant genotype; among these are Isozyme Electrophoresis, Restriction Fragment Length Polymorphisms (RFLPs), Randomly Amplified Polymorphic DNAs (RAPDs), Arbitrarily Primed Polymerase Chain Reaction (AP-PCR), DNA Amplification Fingerprinting (DAF), Sequence Characterized Amplified Regions (SCARs), Amplified Fragment Length Polymorphisms (AFLPs), and Simple Sequence Repeats (SSRs) which are also referred to as Microsatellites.

The most widely used of these laboratory techniques are Isozyme Electrophoresis and RFLPs as discussed in Lee, M., "Inbred Lines of Maize and Their Molecular Markers," The Maize Handbook, (Springer-Verlag, New York, Inc. 1994, at 423-432) incorporated herein by reference. Isozyme Electrophoresis is a useful tool in determining genetic composition, although it has relatively low number of available markers and the low number of allelic variants among maize inbreds. RFLPs have the advantage of revealing an exceptionally high degree of allelic variation in maize and the number of available markers is almost limitless.

Maize RFLP linkage maps have been rapidly constructed and widely implemented in genetic studies. One such study is described in Boppenmaier, et al., "Comparisons among strains of inbreds for RFLPs", Maize Genetics Cooperative Newsletter, 65:1991, pg. 90, is incorporated herein by reference. This study used 101 RFLP markers to analyze the patterns of 2 to 3 different deposits each of five different inbred lines. The inbred lines had been selfed from 9 to 12 times before being adopted into 2 to 3 different breeding programs. It was results from these 2 to 3 different breeding programs that supplied the different deposits for analysis. These five lines were maintained in the separate breeding programs by selfing or sibbing and rogueing off-type plants for an additional one to eight generations. After the RFLP analysis was completed, it was determined the five lines showed 0-2% residual heterozygosity. Although this was a relatively small study, it can be seen using RFLPs that the lines had been highly homozygous prior to the separate strain maintenance.

Inbred maize line PH03D is a white, dent maize inbred that is best suited as a male in crosses for producing first generation F₁ maize hybrids. Inbred maize line PH03D is best adapted to the Southwest and Central Corn Belt regions of the United States and can be used to produce hybrids from approximately 114 relative maturity based on the Comparative Relative Maturity Rating System for harvest moisture of grain.

Inbred maize line PH03D demonstrates excellent male pollen production as an inbred per se. However, inbred maize line PH03D can also be used as a female line. In hybrid combination, PH03D confers excellent yield in most hybrid combinations. Hybrids created using inbred maize line PH03D also exhibit good white grain color. In addition, inbred maize line PH03D is unique as it exhibits a pale green plant color as an inbred per se. In hybrid combination, inbred maize line PH03D attains early flowering for moisture maturity.

The inbred has shown uniformity and stability within the limits of environmental influence for all the traits as described in the Variety Description Information (Table 1) that follows. The inbred has been self-pollinated and ear-rowed a sufficient number of generations with careful attention paid to uniformity of plant type to ensure the homozygosity and phenotypic stability necessary to use in commercial production. The line has been increased both by hand and in isolated fields with continued observation for uniformity. No variant traits have been observed or are expected in PH03D.

Inbred maize line PH03D, being substantially homozygous, can be reproduced by planting seeds of the line, growing the resulting maize plants under self-pollinating or sib-pollinating conditions with adequate isolation, and harvesting the resulting seed, using techniques familiar to the agricultural arts.

                                      TABLE 1     __________________________________________________________________________     VARIETY DESCRIPTION INFORMATION     VARIETY = PH03D     __________________________________________________________________________       TYPE:           (describe intermediate types in Comments section):       2   1 = Sweet 2 = Dent 3 = Flint 4 = Flour 5 = Pop 6 = Ornamental       MATURITY:     DAYS  HEAT UNITS     075   1,495.5                  From emergence to 50% of plants in silk     072   1,427.8                  From emergence to 50% of plants in pollen     006   0,139.8                  From 10% to 90% polIen shed     066   1,159.0                  From 50% silk to harvest at 25% moisture       PLANT:                                   Standard                                                       Sample                Deviation                       Size       0,198.5           cm   Plant Height (to tassel tip)    7.05   4       0,078.8           cm   Ear Height (to base of top ear node)                                                6.29   4       0,017.5           cm   Length of Top Ear Internode     0.68   20          1     Avemge Number of Tillens        0.00   4          1.0   Average Number of Ears per Stalk                                                0.00   4          3.0   Anthocyanin of Brace Roots: 1 = Absent 2 = Faint 3 = Moderate                4 = Dark       LEAF:                                    Standard                                                       Sample                                                Deviation                                                       Size       009.1           cm   Width of Ear Node Leaf          0.20   20       065.8           cm   Length of Ear Node Leaf         1.80   20        05.3    Number of leaves above top ear  0.30   20       033.8    Degrees Leaf Angle (measure from 2nd leaf above                                                9.91    4                ear at anthesis to stalk abcve leaf)       02       Leaf Color Medium Green (Munsell code) 5GY44       2.0      Leaf Sheath Pubescence (Rate on scale from 1 = none to 9 =                like peach fuzz)       6.3      Marginal Waves (Rate on scale from 1 = none to 9 = many)       5.3      Longitudinal Creases (Rate on scale from 1 = none to 9 = many)       TASSEL                                   Standard                                                       Sample                                                Deviation                                                       Size       06.6     Number of Primary Lateral Bunches                                                1.57   20       027.9    Bunch Angle from Central Spike  13.64  4       51.6           cm   Tassel Length (from top leaf collar to tassel                                                5.46   4       8.0      Pollen Shed (rate on scale from 0 = male sterile                to 9 = heavy shed)       07       Anther Color Yellow (Munsell code)     10Y96       01       Glume Color Light Green (Munsell code) 5GY66       1.0      Bar Glumes (Glume Bands): 1 = Absent 2 = Present       21       Peduncle Length (cm from top leaf to basal branches)     6a.       EAR (Unhusked Data):     11         Silk Color (3 days after emergence)                                     Pink     (Munsell code)                                                           7.5R76     1          Fresh Husk Color (25 days after 50% silking)                                     Light Green                                              (Munsell code)                                                           5GY78     21         Dry Husk Color (65 days after 50% silking)                                     Buff     (Munsell code)                                                           2.5Y8.54     3          Postion of Ear at Dry Husk Stage: 1 = Upright 2 = Horizontal 3                = Pendant                       Pendant     5          Husk Tightness (Rate of Scale from 1 = very loose to 9 = very                tight)     2          Husk Extension (at harvest): 1 = Short (ears exposed) 2 =                Medium (<8 cm)                3 = Long (8-10 cm beyond ear tip) 4 = Very Long (>10                                                Medium     6b.       EAR (Husked Ear Data):                   Standard                                                       Sample                                                Deviation                                                       Size     15   cm Ear Length                         1.83   20     38   mm Ear Diameter at mid-point          2.22   20     92   gm Ear Weight                         16.07  20     15      Number of Kenel Rows               0.89   20     2       Kernel Rows: 1 = Indistinct 2 = Distinct      Distinct     1       Row Alignment: 1 = Straight 2 = Slightiy Curved 3                                                           Straight     10   cm Shank Length                       2.66   20     2       Ear Taper: 1 = Slight 2 = Average 3 = Extreme Average             Ear Taper: 1 = Slight 2 = Average 3 = Extreme Average       KERNEL (Dried):                          Standard                                                       Sample                                                Deviation                                                       Size     10   mm Kemel Length                       0.68   20     7    mm Kemel Width                        0.53   20     4    mm Kernei Thickness                   0.48   20     9       % Round Kerneis (Shape Grade)      7.18   4     1       Aleurone Color Pattern: 1 = Homozygous 2 = Segregating                                                Homozygous     19     Aluerone Color                      White                     (MunseIl code)                                                           2.SY8.52     19     Hard Endospenn Color                      White                     (Munsell code)                                                           2.SY8.52     3      Endospenn Type:                      Normal Starch            1 = Sweet (Sul) 2 = Extra Sweet (sh2) 3 = Normal Starch            4 = High Amylose Starch 5 = Waxy Starch 6 = High Protein            7 = High Lysine 8=Super Sweet (se) 9=High Oil            10 = Other.sub.------       20 gm Weight per 100 Kernels (unsized sample)                                                2.99   4       COB:                                     Standard                                                       Sample                                                Deviation Size       22 mm Cob Diameter at mid-point          0.86   20     19     Cob Color                 White                          (Munsell code)                                                           5Y91     2      Cob Strength 1 = Weak 2 = Strong       DISEASE RESISTANCE (Rate from 1 (most susceptible) to 9 (most       reaistant); leave blank                if not tested; leave Race or Strain Options blank if       polygenic):     A.  Leaf Blights, Wifts, and Local Infection Diseases           Anthracnose Leaf Blight (Colletotrichum graminicofa)     6     Common Rust (Puccinia sorghi)           Common Smut (Ustifago           maydis Eyespot (Kabatiella zeae)     8     Goss's Wilt (Cfavibacter michiganense spp. nebraskense)     4     Gray Leaf Spot (Cercospora zeamaydis)           Helminthosporium Leaf Spot (Bipofaris zeicola) Race----     6     Northern Leaf Blight (Exserohilum turcicum) Race----     4     Southern Leaf Blight (Bipolaris maydis) Race----           Southern Rust (Puccinia poiysora)     7     Stewart's Wift (Erwinia stewartii)           Other (Specify)     B.  Systemic Diseases     5     Corn Lethal Necrosis (MCMV and MDMV)           Head Smut (Sphacelotheca reiliana)           Maize Chlorotic Dwarf Virus (MDV)           Maize Chlorotic Mottte Virus (MCMV)     3     Maize Dwarf Mosaic Virus (MDMV)           Sorghum Downy Mildew of Com (Peronosclersspora sorghi)           other (Specify)----     C.  Stalk Rots     4     Anthracncse Stalk Rot (Colietotrichum graminicoia)           Dipiodia Stalk Rot (Stenocarpeila maydis)           Fusarium Stalk Rot (Fusarium monilWonne)           Gibberelia Stalk Rot (Gibberella zeae)           Other (Specify)     D.  Ear and Kernel Rots           Aspergillus Ear and Kernel Rot (Aspergillus fiavus)     5     Diplodia Ear Rot (Stenocarplia maydis)     5     Fusarium Ear and Kemei Rot (Fusarium moniliforme)           Gibberella Ear Root (Gibberella Zeae)           Other (Specify)           Banks grass Mite (Oiigonychus pratensis)           Corn Worm (Helicoverpa zea)           Leaf Feeding           Silk Feeding           mg larvai wi.           Ear Damage           Corn Leaf Aphid (Rhopalosiphum maidis)           Corn Sap Beetle (Carpaphiius dimidiatus)           European Com Borer (Ostrinia nubilalis)     4     1st Generation (Typically Whorl Leaf Feeding)           2nd Generation (Typically Leaf Sheath-Collar Feeding)           Staik Tunneling           cm tunneled/plant           Fail Armyworm (Spodoptera truqiperda)           Leaf Feeding           Silk Feeding           mg larval wt.           Maize Weevil (Sitophiius zeamaize           Northern Rootworm (Diabrotica berberi)           Southern Rootworm (Diabrotica undecimpunctata)           Southwestern Corn Borer (Diatreaea grandioseiia)           Leaf Feeding           Stalk Tunneiing           cm tunneled/plant           Two spotted Spider Mite (Tetranychus urticae)           Western Rootworm (Diabrotica virgifrea virgifera)           Other (Specify)     11. AGRONOMIC TRAITS:     3     Staygreen (at 65 days after anthesis) (Rate on a scale from 1           =worst to           excellent)     1.0   % Dropped Ears (at 65 days after anthesis)           % Pre-anthesis Brittle Snapping           % Pre-anthesis Root Lodging     13.4  Posi#nthesis Root Lodging (at 55 days after anthesis)     4,100 Kg/ha Yieid (at 12-13% grain moisture)     __________________________________________________________________________      *In interpreting the foregoing color designations, reference may be had t      the Munsell Glossy Book of Color, a standard color reference.

Industrial Applicability

This invention also is directed to methods for producing a maize plant by crossing a first parent maize plant with a second parent maize plant wherein either the first or second parent maize plant is an inbred maize plant of the line PH03D. Further, both first and second parent maize plants can come from the inbred maize line PH03D. Thus, any such methods using the inbred maize line PH03D are part of this invention: selfing, backcrosses, hybrid production, crosses to populations, and the like. All plants produced using inbred maize line PH03D as a parent are within the scope of this invention. Advantageously, the inbred maize line is used in crosses with other, different, maize inbreds to produce first generation (F₁) maize hybrid seeds and plants with superior characteristics.

As used herein, the term plant includes plant cells, plant protoplasts, plant cell tissue cultures from which maize plants can be regenerated, plant calli, plant clumps, and plant cells that are intact in plants or parts of plants, such as embryos, pollen, ovules, flowers, kernels, ears, cobs, leaves, husks, stalks, roots, root tips, anthers, silk and the like.

Duncan, Williams, Zehr, and Widholm, Planta (1985) 165:322-332 reflects that 97% of the plants cultured that produced callus were capable of plant regeneration. Subsequent experiments with both inbreds and hybrids produced 91% regenerable callus that produced plants. In a further study in 1988, Songstad, Duncan & Widholm in Plant Cell Reports (1988), 7:262-265 reports several media additions that enhance regenerability of callus of two inbred lines. Other published reports also indicated that "nontraditional" tissues are capable of producing somatic embryogenesis and plant regeneration. K. P. Rao, et al., Maize Genetics Cooperation Newsletter, 60:64-65 (1986), refers to somatic embryogenesis from glume callus cultures and B. V. Conger, et al., Plant Cell Reports, 6:345-347 (1987) indicates somatic embryogenesis from the tissue cultures of maize leaf segments. Thus, it is clear from the literature that the state of the art is such that these methods of obtaining plants are, and were, "conventional" in the sense that they are routinely used and have a very high rate of success.

Tissue culture of maize is described in European Patent Application, publication 160,390, incorporated herein by reference. Maize tissue culture procedures are also described in Green and Rhodes, "Plant Regeneration in Tissue Culture of Maize," Maize for Biological Research (Plant Molecular Biology Association, Charlottesville, Va. 1982, at 367-372) and in Duncan, et al., "The Production of Callus Capable of Plant Regeneration from Immature Embryos of Numerous Zea Mays Genotypes," 165 Planta 322-332 (1985). Thus, another aspect of this invention is to provide cells which upon growth and differentiation produce maize plants having the physiological and morphological characteristics of inbred line PH03D.

Maize is used as human food, livestock feed, and as raw material in industry. The food uses of maize, in addition to human consumption of maize kernels, include both products of dry- and wet-milling industries. The principal products of maize dry milling are grits, meal and flour. The maize wet-milling industry can provide maize starch, maize syrups, and dextrose for food use. Maize oil is recovered from maize germ, which is a by-product of both dry- and wet-milling industries.

Maize, including both grain and non-grain portions of the plant, is also used extensively as livestock feed, primarily for beef cattle, dairy cattle, hogs, and poultry.

Industrial uses of maize include production of ethanol, maize starch in the wet-milling industry and maize flour in the dry-milling industry. The industrial applications of maize starch and flour are based on functional properties, such as viscosity, film formation, adhesive properties, and ability to suspend particles. The maize starch and flour have application in the paper and textile industries. Other industrial uses include applications in adhesives, building materials, foundry binders, laundry starches, explosives, oil-well muds, and other mining applications.

Plant parts other than the grain of maize are also used in industry: for example, stalks and husks are made into paper and wallboard and cobs are used for fuel and to make charcoal.

The seed of inbred maize line PH03D, the plant produced from the inbred seed, the hybrid maize plant produced from the crossing of the inbred, hybrid seed, and various parts of the hybrid maize plant can be utilized for human food, livestock feed, and as a raw material in industry.

PERFORMANCE EXAMPLES OF PH03D

In the examples that follow, the traits and characteristics of inbred maize line PH03D are given as a line. The data collected on inbred maize line PH03D is presented for the key characteristics and traits.

Inbred Comparisons

The results in Table 2A compare inbred PH03D to inbred PH15A. The inbred per se results show inbred PH03D demonstrates lower harvest moisture than inbred PH15A. Inbred PH03D demonstrates a significantly earlier GDU to shed than inbred PH15A. Although inbred PH03D has a smaller tassel size than inbred PH15A, inbred PH03D has greater pollen weight than inbred PH15A. Inbred PH03D demonstrates significantly superior resistance to brittle stalk as compared to inbred PH15A.

The results in Table 2B compare inbred PH03D to inbred PHAP1. Inbred PH03D demonstrates an earlier GDU to shed than inbred PHAP1. The inbred per se results for inbred PH03D and inbred PHAP1 both show excellent pollen weight. Both inbred PH03D and inbred PHAP1 demonstrate good resistance to brittle stalk. Inbred PH03D exhibits significantly better Southern Leaf Blight resistance than inbred PHAP1.

The inbred per se results in Table 2C compare inbred PH03D to its parent, inbred PHT60. The results show inbred PH03D demonstrates significantly lower harvest moisture than inbred PHT60. Inbred PH03D exhibits significantly superior pollen weight than inbred PHT60. In addition, inbred PH03D exhibits significantly greater pollen score and larger tassel size than inbred PHT60.

The results in Table 3A compare inbred PH03D to its parent, inbred PHT60, when each inbred is crossed to the same tester lines. The PH03D hybrids are significantly higher yielding with significantly lower harvest moisture than the PHT60 hybrids. The PH03D hybrids exhibit better resistance to brittle stalk than the PHT60 hybrids.

The results in Table 3B compare inbred PH03D and inbred PHK93, when each inbred is crossed to the same tester lines. Although the PH03D hybrids are lower yielding, PH03D hybrids exhibit significantly lower harvest moisture and greater test weight than the PHK93 hybrids. Both PH03D hybrids and PHK93 hybrids demonstrate above average resistance to brittle stalk.

The results in Table 4A compare inbred PHN18 crossed to inbred PH03D and inbred PHK93 crossed to PHN34. The PHN18/PH03D hybrid is significantly higher yielding, has significantly higher test weight and has significantly lower harvest moisture than the PHK93/PHN34 hybrid. In addition, the PHN18/PH03D hybrid exhibits significantly superior seedling vigor than the PHK93/PHN34 hybrid. The PHN18/PH03D hybrid has earlier than average flowering (GDU Shed and GDU Silk) and is significantly earlier in flowering than the PHK93/PHN34 hybrid. The PHN18/PH03d hybrid has above average grain appearance.

The results in Table 4B compare inbred PHN18 crossed to inbred PH03D and inbred PH19A crossed to PH15A. The results show that the PHN18/PH03D hybrid is significantly higher yielding and has significantly greater seedling vigor than the PH19A/PH15A hybrid. The PHN18/PH03D hybrid also has a significantly higher resistance to Gray Leaf Spot than the PH19A/PH15A hybrid. The PHN18/PH03D hybrid has earlier than average flowering (GDU Shed and GDU Silk) and is significantly earlier in flowering than the PH19A/PH15A hybrid. The PHN18/PH03D hybrid demonstrates significantly better resistance to stalk lodging than the PH19A/PH15A hybrid. The PHN18/PH03D hybrid exhibits significantly better grain appearance than the PH19A/PH15A hybrid.

The results in Table 4C compare inbred PHN18 crossed to inbred PH03D and inbred PHN18 crossed to PHT60. The results show that the PHN18/PH03D hybrid is significantly higher yielding, with significantly lower harvest moisture than the PHN18/PHT60 hybrid. The PHN18/PH03D hybrid also has better resistance to brittle stalk than the PHN18/PHT60 hybrid. Both hybrids have earlier than average flowering (GDU Shed and GDU Silk).

                                      TABLE 2A     __________________________________________________________________________     PAIRED INBRED COMPARISON REPORT     VARIETY #1 = PH03D     VARIETY #2 = PH15A                BU  BU      TST SDG EST TIL GDU GDU                ACR ACR MST WT  VGR CNT LER SHD SLK                ABS % MN                        ABS ABS ABS ABS ABS ABS,                                                ABS     __________________________________________________________________________     TOTAL SUM            1   39.9                    85  20.1                            55.9                                4.5 30.2                                        1.5 151.7                                                157.3            2   34.8                    77  22.9                            54.8                                4.6 25.7                                        4.2 158.0                                                158.8            LOCS                9   9   9   9   29  48  38  56  55            REPS                11  11  11  11  32  71  43  62  60            DIFF                5.0 9   2.7 1.1 0.1 4.5 2.7 6.3 1.4            PR > T                .428                    .508                        .023+                            .205                                .843                                    .000#                                        .082+                                            .000#                                                .085*     __________________________________________________________________________                POL POL POL TAS PLT EAR RT  STA STK                WT  WT  SC  SZ  HT  HT  LDG,                                            GRN LDG                ABS % MN                        ABS ABS ABS ABS ABS ABS ABS     __________________________________________________________________________     TOTAL SUM            1   193.0                    109 6.8 5.6 80.7                                    32.9                                        92.8                                            3.2 94.6            2   167.7                    98  6.4 6.8 82.6                                    38.1                                        97.5                                            4.9 9,1.2            LOCS                5   5*  9   27  23  21  3   18  6            REPS                5   5   9   29  28  26  4   20  9            DIFF                25.3                    12  0.3 1.2 1.9 5.3 4.7 1.7 3.3            PR > T                .396                    .521                        .580                            .000#                                .380                                    .043+                                        .511                                            .029+                                                .577     __________________________________________________________________________                BRT GRN SCT EAR TEX EAR BAR DRP GLF                STK AFP GRN SZ  EAR MLD PLT EAR SPT                ABS ABS ABS ABS ABS ABS ABS ABS ABS     __________________________________________________________________________     TOTAL SUM            1   98.0                    5.8 6.8 5.6 5.8 6.8 96.2                                            99.3                                                3.5            2   77.6                    6.6 5.8 4.0 6.6 7.3 84.2                                            100.0                                                2.9            LOCS                11  7   13  9   9   13  11  5   18            REPS                12  9   15  9   9   15  11  8   29            DIFF                20.4                    0.9 1.0 1.6 0.8 0.5 12.0                                            0.7 0.6            PR > T                .008#                    .383                        .217                            .015+                                .008#                                    .235                                        .030+                                            .210                                                .170                NLF SLF GOS STW ANT HD      MDM FUS                BLT BLT WLT WLT ROT SMT CLN CPX ERS                ABS ABS ABS ABS ABS ABS ABS ABS ABS     __________________________________________________________________________     TOTAL SUM            1   5.4 4.3 8.0 7.6 4.3 96.7                                        4.5 3.3 4.4            2   6.3 5.0 7.0 6.5 4.4 59.9                                        7.0 3.0 5.3            LOCS                8   5   2   4   6   2   1   2   4            REPS                16  10  3   6   12  6   2   4   7            DIFF                0.8 0.7 1.0 0.5 0.2 36.8                                        2.5 0.3 0.9            PR > T                .068*                    .206                        .000#                            .474                                .771                                    .293                                        .500                                            .441                DIP COM ECB                ERS RST 1LF                ABS ABS ABS     __________________________________________________________________________     TOTAL SUM            1   5.0 6.0 5.0     2      4.5 7.0 7.0     LOCS   1   1   1     REPS   2   2   1     DIFF   0.5 1.0 2.0     PR > T     __________________________________________________________________________      * = 10% SIG      + = 5% SIG      # = 1% SIG

                                      TABLE 2B     __________________________________________________________________________     PAIRED INBRED COMPARISON REPORT     VARIETY #1 = PH03D     VARIETY #2 = PHAP1                SDG EST TIL GDU GDU POL POL POL TAS                VGR CNT LER SHD SLK WT  WT  SC  SZ                ABS ABS ABS ABS ABS ABS % MN                                            ABS ABS     __________________________________________________________________________     TOTAL SUM            1   5.1 29.5                        1.7 151.1                                156.4                                    264.3                                        156 6.7 5.6            2   4.5 27.6                        2.9 152.4                                155.6                                    251.3                                        140 7.6 7.0            LOCS                19  39  31  46  45  5   5   13  26            REPS                20  55  33  50  48  5   5   13  28            DIFF                0.6 1.9 1.2 1.3 0.9 13.0                                        16  0.9 1.3            PR > T                .046+                    .023+                        .378                            .053+                                .231                                    .757                                        .531                                            .005#                                                .000#     __________________________________________________________________________                PLT EAR RT  STA BRT SCT EAR TEX EAR                HT  HT  LDG GRN STK GRN SZ  EAR MLD                ABS ABS ABS ABS ABS ABS ABS ABS ABS     __________________________________________________________________________     TOTAL SUM            1   82.8                    34.9                        100.0                            3.1 100.0                                    6.8 5.6 5.8 6.8            2   81.7                    33.4                        91.5                            5.B 99.2                                    7.4 5.6 6.9 7.4            LOCS                16  13  2   13  10  13  9   9   *13            REPS                19  16  3   13  11  15  9   9   15            DIFF                1.1 1.5 8.5 2.8 0.8 0.6 0.0 1.1 0.5            PR > T                .301                    .157                        .278                            .004#                                .171                                    .180                                        .999                                            .007#                                                .188     __________________________________________________________________________                BAR GLF NLF SLF GOS STW ANT HD                PLT SPT BLT BLT WLT WLT ROT SMT CLN                ABS ABS ABS ABS ABS ABS ABS ABS ABS     __________________________________________________________________________     TOTAL SUM            1   96.2                    3.6 5.4 4.3 8.0 7.0 4.1 96.7                                                4.5            2   91.1                    3.9 4.6 1.5 8.0 5.4 3.4 95.2                                                7.5            LOCS                11  19  8   5   2   4   7   2   1            REPS                11  30  16  1O  3   6   13  6   2            DIFF                5.1 *0.4                        0.9 2.8 0.0 1.6 0.6 1.4 3.0            PR > T                .124                    .197                        .139                            .003#                                .999                                    .041+                                        .298                                            .678     __________________________________________________________________________                MDM FUS DIP COM ECB                CPX ERS ERS RST 1LF                ABS ABS ABS ABS ABS     __________________________________________________________________________     TOTAL SUM            1   3.3 4.5 5.0 6.0 4.5            2   3.8 5.2 3.5 6.5 6.0            LOCS                2   5   1   1   2            REPS                4   8   2   2   2            DIFF                0.5 0.7 1.5 0.5 1.5            PR > T                .500                    .499        .205     __________________________________________________________________________      * = 10% SIG      + = 5% SIG      # = 1% SIG

                                      TABLE 2C     __________________________________________________________________________     PAIRED INBRED COMPARISON REPORT     VARIETY #1 = PH03D     VARIETY #2 = PHT60                BU  BU      TST SDG EST TIL GDU GDU                ACR ACR MST WT  VGR CNT LER SHD SLK                ABS % MN                        ABS ABS ABS ABS ABS ABS ABS     __________________________________________________________________________     TOTAL SUM            1   69.2                    102 17.3                            58.7                                4.7 37.5                                        1.1 151.2                                                156.6            2   64.0                    98  20.2                            58.7                                5.9 37.0                                        0.6 145.9                                                149.9            LOCS                15  15  19  14  36  58  50  63  62            REPS                26  26  30  25  45  69  61  69  67            DIFF                5.1 4   2.9 0.0 1.2 0.5 0.5 5.3 6.7            PR > T                .421                    .684                        .0O1#                            .999                                .000#                                    .515                                        .211                                            .000#                                                .000#     __________________________________________________________________________                POL POL POL TAS PLT EAR RT  STA STK                WT  WT  SC  SZ  HT  HT  LDG GRN LDG                ABS % MN                        ABS ABS ABS ABS ABS ABS ABS     __________________________________________________________________________     TOTAL SUM            1   271.8                    147 6.7 5.5 81.3                                    32.7                                        100.0                                            3.2 92.0            2   127.6                    65  5.9 4.8 82.8                                    29.5                                        100.0                                            5.5 95.3            LOCS                9   9   13  29  31  27  4   24  11            REPS                9   9   13  31  42  38  6   31  19            DIFF                144.3                    82  0.8 0.7 1.5 3.2 0.0 2.4 3.3            PR > T                .003#                    .003#                        .008#                            .012+                                .117                                    .000#                                        .999                                            .000#                                                .195     __________________________________________________________________________                BRT GRN SCT EAR TEX EAR BAR DRP GLF                STK APP GRN SZ  EAR MLD PLT EAR SPT                ABS ABS ABS ABS ABS ABS ABS ABS ABS     __________________________________________________________________________     TOTAL SUM            1   98.5                    5.9 6.8 5.7 5.8 6.8 96.6                                            99.3                                                3.6            2   97.2                    6.6 7.1 4.9 6.4 6.8 95.8                                            1O0.0                                                4.2            LOCS                15  9   13  9   9   13  21  5   19            REPS                18  14  15  9   9   15  23  8   30            DIFF                1.4 0.7 0.2 0.8 0.7 0.0 0.8 0.7 0.6            PR > T                .264                    .343                        .584                            .111                                .058#                                    .999                                        .729                                            .210                                                .014+     __________________________________________________________________________                NLF SLF GOS STW ANT HD      MDM FUS                BLT BLT WLT WLT ROT SMT CLN CPX ERS                ABS ABS ABS ABS ABS ABS ABS ABS ABS     __________________________________________________________________________     TOTAL SUM            1   5.4 4.3 8.0 7.0 4.3 96.7                                        4.5 3.3 4.4            2   4.9 5.4 7.8 6.9 5.4 98.5                                        3.0 2.8 5.8            LOCS                8   5   2   4   6   2   1   2   4            REPS                16  10  3   6   12  6   2   4   7            DIFF                0.6 1.1 0.3 0.1 1.2 1.9 1.5 0.5 1.4            PR > T                .051*                    .040+                        .500                            .789                                .013+                                    .239                                        .500                                            .377     __________________________________________________________________________                DIP COM ECB                ERS RST 1LF                ABS ABS ABS     __________________________________________________________________________     TOTAL SUM            1   5.0 6.0 4.5            2   3.5 5.0 4.5            LOCS                1   1   2            REPS                2   2   2            DIFF                1.5 1.0 0.0            PR > T      .999     __________________________________________________________________________      * = 10% SIG      + = 5% SIG      # = 1% SIG

                                      TABLE 3A     __________________________________________________________________________     Average Inbred By Tester Performance Comparing PH03D To PHT60 Crossed     To The Same Inbred Testers And Grown In The Same Experiments.                SEL     BU  BU  PRM     TST SDG EST GDU                IND PRM ACR ACR SHD MST WT  VGR CNT SHD                % MN                    ABS ABS % MN                                ABS % MN                                        ABS % MN                                                % MN                                                    % MN     __________________________________________________________________________     TOTAL SUM            REPS                1   4   114 114 1   120 80  47  70  19            LOCS                1   1   .107                            107 1   .112                                        72  40  63  17            PH03D                99  113 154 99  112 97  58  97  102 99            PHT60                90  114 143 92  111 101 58  113 101 9B            DIFF                9   1   11  7   1   4   0   1S  2   1            PR > T      0.00                            0.00    0.00                                        0.99                                            0.00                                                0.19                                                    0.24     __________________________________________________________________________                GDU STK PLT EAR RT  STA STK BRT GRN STW                SLK CNT HT  HT  LDG GRN LDG STK APP WLT                % MN                    % MN                        % MN                            % MN                                % MN                                    % MN                                        % MN#                                            % MN                                                % MN                                                    ABS     __________________________________________________________________________     TOTAL SUM            REPS                12  130 60  58  32  33  80  9   9   1            LOCS                11  119 58  57  30  33  73  9   9   1            PH03D                99  100 96  100 85  89  102 108 103 8            PHT60                98  101 97  96  89  116 105 97  121 7            DIFF                1   1   1   4   4   27  3   11  18  1            PR > T                0.09                    0.43                        0.31                            0.00                                0.41                                    0.00                                        0.01                                            0.02                                                0.05     __________________________________________________________________________                SOU ECB DRP GLF                RST 2SC EAR SPT                ABS ABS % MN                            ABS     __________________________________________________________________________     TOTAL SUM            REPS                1   7   20  6            LOCS                1   7   19  6            PH03D                6   5   100 5            PHT60                6   7   100 5            DIFF                0   1   0   0            PR > T                0.99                    0.02                        0.99                            0.99     __________________________________________________________________________      *PR > T values are valid only for comparisons with Locs >= 10.

                                      TABLE 3B     __________________________________________________________________________     Average Inbred By Tester Performance Comparing PH03D To PHK93 Crossed     To The Same Inbred Testers And Grown In The Same Experiments.                SEL     BU  BU  PRM     TST SDG EST GDU                IND PRM ACR ACR SHD MST WT  VGR CNT SHD                % MN                    ABS ABS % MN                                ABS % MN                                        ABS % MN                                                % MN                                                    % MN     __________________________________________________________________________     TOTAL SUM            REPS                1   1   45  45  1   45  26  4   16            LOCS                1   1   45  45  1   45  26  4   16  6            PHO3D                99  113 170 97  112 91  59  101 103 1OO            PHK93                104 116 180 103 112 103 58  101 100 101            DIFF                5   3   10  6   0   12  1   1   2   1            PR > T      0.00                            0.00                                0.99                                    0.00                                        0.01                                            9.91                                                0.18                                                    0.18     __________________________________________________________________________                GDU STK PLT EAR RT  STA STK BRT GRN DRP                SLK CNT HT  HT  LDG GRN LDG STK APP EAR                % MN                    % MN                        % MN                            % MN                                % MN                                    % MN                                        % MN                                            % MN                                                % MN                                                    % MN     __________________________________________________________________________     TOTAL SUM            REPS                4   48  23  23  14  22  24  6   6   2            LOCS                4   48  23  23  14  22  24  6   6   2            PH03D                100 101 96  99  81  73  100 108 80  100            PHK93                101 98  101 102 93  108 101 107 117 100            DIFF                1   3   5   3   12  35  1   1   37  0            PR > T                0.39                    0.02                        0.00                            0.09                                0.22                                    0.00                                        0.72                                            0.68                                                0.08                                                    0.99     __________________________________________________________________________                GLF                SPT                ABS     __________________________________________________________________________     TOTAL SUM            REPS                2            LOCS                2            PHO3D                5            PHK93                7            DIFF                2            PR > T     __________________________________________________________________________      *PR > T values are valid only for comparisons with Locs >= 10.

                                      TABLE 4A     __________________________________________________________________________     INBREDS IN HYBRID COMBINATION REPORT     VARIETY #1 = FHN18/PH03D     VARIETY #2 = PHK93/PHN34                    PRM BU  BU      TST SDG EST GDU                FRM SHD ACR ACR MST WT  VGR CNT SHD                ABS ABS ABS % MN                                % MN                                    ABS % MN                                            % MN                                                % MN     __________________________________________________________________________     TOTAL SUM            1   115 111 166.2                            109 101 57.4                                        105 100 99            2   116 114 145.2                            95  105 56.7                                        80  101 102            LOCS                93  31  488 488 501 196 122 132 61            REPS                93  31  498 498 513 204 129 140 68            DIFF                1   3   20.9                            14  5   0.7 25  1   4            PR > T                .000#                    .000#                        .000.#                            .000#                                .000#                                    .000#                                        .000#                                            .219                                                .000#     __________________________________________________________________________                GDU STK PLT EAR RT  STA STK BRT GRN                SLK CNT HT  HT  LDG GRN LDG STK APP                % MN                    #MN % MN                            % MN                                % MN                                    % MN                                        % MN                                            % MN                                                % MN     __________________________________________________________________________     TOTAL SUM            1   99  101 97  99  90  117 104 99  104            2   104 100 101 101 111 112 104 95  116            LOCS                29  460 141 134 108 135 202 42  18            REPS                30  488 143 135 111 135 209 44  18            DIFF                6   1   4   2   20  4   0   4   12            PR > T                .000#                    .207                        .000#                            .063+                                .000#                                    .284                                        .999                                            .296                                                .049+     __________________________________________________________________________                DRP GLF NLF SLF GOS STW ANT HD                EAR SFT BLT BLT WLT WLT ROT SMT CLN                % MN                    ABS ABS ABS ABS ABS ABS ABS ABS     __________________________________________________________________________     TOTAL SUM            1   100 4.8 3.3 4.8 8.0 7.0 4.1 100.0                                                6.5            2   100 5.6 5.0 5.3 7.0 6.3 3.5 95.2                                                8.0            LOCS                38  21  3   4   1   3   4   1   1            REPS                39  26  6   7   1   4   7   2   2            DIFF                0   0.9 1.7 0.5 1.0 0.7 0.6 4.8 1.5            PR > T                .999                    .011+                        .362                            .514    .184                                        .342     __________________________________________________________________________                MDM FUS GIB COM SOU ECB ECB                CPX ERS ERS RST RST DPE 2SC                ABS ABS ABS ABS ABS ABS ABS     __________________________________________________________________________     TOTAL SUM            1   2.9 4.2 8.0 5.3 4.0 98.7                                        5.3            2   3.0 4.5 8.5 6.0 4.7 100.0                                        6.3            LOCS                2   6   1   2   3   3   9            REPS                6   B   2   3   5   3   9            DIFF                0.1 0.3 0.5 0.8 0.7 1.3 1.0            PR > T                .500                    .750    .500                                .057+                                    .423                                        .053     __________________________________________________________________________      * = 10% SIG      + = 5% SIG      # = 1% SIG

                                      TABLE 4B     __________________________________________________________________________     INBREDS IN HYBRID COMBINATION REPORT     VARIETY #1 = FHN18/FH03D     VARIETY #2 = FH19A/FH15A                    FRM BU  BU      TST SDG EST GDU                FRM SHD ACR ACR MST WT  VGR CNT SHD                ABS ABS ABS % MN                                % MN                                    ABS % MN                                            % MN                                                % MN     __________________________________________________________________________     TOTAL SUM            1   114 111 154.0                            108 100 57.4                                        103 100 99            2   110 113 128.5                            89  88  57.3                                        87  93  101            LOCS                44  34  275 275 290 127 104 114 66            REFS                44  34  283 283 299 133 109 118 73            DIFF                4   2   25.5                            19  12  0.1 16  7   2            FR > T                .000#                    .000#                        .000#                            .000#                                .000#                                    .442                                        .000#                                            .000#                                                .000#     __________________________________________________________________________                GDU STK FLT EAR RT  STA STK BRT GRN                SLK CNT HT  HT  LDG GRN LDG STK AFP                % MN                    % MN                        % MN                            % MN                                % MN                                    % MN                                        % MN                                            % MN                                                % MN     __________________________________________________________________________     TOTAL SUM            1   99  101 98  100 85  115 104 98  102            2   101 94  101 101 109 49  94  104 81            LOCS                32  294 113 96  69  80  150 29  16            REFS                32  322 115 97  70  80  153 33  16            DIFF                2   7   3   1   24  66  11  6   21            FR > T                .000#                    .000#                        .000#                            .333                                .000#                                    .000#                                        .000#                                            .012+                                                .008#     __________________________________________________________________________                DRF GLF SLF STW MDM FUS GIB COM SOU                EAR SFT BLT WLT CFX ERS ERS RST RST                % MN                    ABS ABS ABS ABS ABS ABS ABS ABS     __________________________________________________________________________     TOTAL SUM            1   100 5.2 4.0 8.0 3.0 4.7 8.0 6.0 6.0            2   100 2.5 5.0 6.5 2.5 7.2 8.5 6.0 4.0            LOCS                40  18  1   2   1   6   1   1   1            REFS                41  18  1   2   2   6   2   1   1            DIFF                0   2.7 1.0 1.5 0.5 2.5 0.5 0.0 2.0            FR > T                .999                    .000#   .205                                .032+     __________________________________________________________________________                ECB ECB                DPE 2SC                ABS ABS     __________________________________________________________________________     TOTAL SUM            1   98.7                    5.4            2   99.3                    4.9            LOCS                3   8            REPS                3   8            DIFF                0.6 0.5            PR > T                .423                    .316     __________________________________________________________________________      * = 10% SIG      + = 5% SIG      # = 1% SIG

                                      TABLE 4C     __________________________________________________________________________     INBREDS IN HYBRID COMBINATION REFORT     VARIETY #1 = PHN18/PH03D     VARIETY #2 = PHN18/PHT60                    PRM BU  BU      TST SDG EST GDU                PRM SHD ACR ACR MST WT  VGR CNT SHD                ABS ABS ABS % MN                                % MN                                    ABS % MN                                            % MN                                                % MN     __________________________________________________________________________     TOTAL SUM            1   115 111 164.2                            108 101 57.3                                        105 100 99            2   115 110 149.1                            99  103 57.8                                        118 101 97            LOCS                81  33  441 441 453 196 130 133 67            REPS                81  33  451 451 464 204 137 140 73            DIFF                1   1   15.1                            9   2   0.5 13  1   2            PR > T                .000#                    .000#                        .000#                            .000#                                .000#                                    .000#                                        .000#                                            .291                                                .000#     __________________________________________________________________________                GDU STK PLT EAR RT  STA STK BRT GRN                SLK CNT HT  HT  LDG GRN LDG STK AFP                % MN                    % MN                        % MN                            % MN                                % MN                                    % MN                                        % MN                                            % MN                                                % MN     __________________________________________________________________________     TOTAL SUM            1   99  101 97  99  90  117 104 98  106            2   97  101 96  95  98  130 106 95  113            LOCS                30  456 151 132 110 144 206 47  16            REPS                31  488 153 133 113 144 214 51  16            DIFF                2   0   1   4   8   14  2   3   7            PR > T                .000#                    .999                        .016+                            .000#                                .000#                                    .000#                                        .000#                                            .090*                                                .306     __________________________________________________________________________                DRP GLF NLF SLF GOS STW ANT HD                EAR SPT BLT BLT WLT WLT ROT SMT CLN                % MN                    ABS ABS ABS ABS ABS ABS ABS ABS     __________________________________________________________________________     TOTAL SUM            1   100 5.0 3.3 4.8 8.0 7.0 4.1 100.0                                                6.5            2   100 4.7 3.7 6.1 7.0 6.7 4.1 100.0                                                3.5            LOCS                41  22  3   4   1   3   4   1   1            REFS                42  27  6   7   2   4   7   2   2            DIFF                0   0.3 0.3 1.4 1.0 0.3 0.0 0.0 3.0            PR > T                .999                    .180                        .529                            .102    .423                                        .999     __________________________________________________________________________                 MDM  FUS  GIB  COM  SOU  ECB  ECB                 CPX  ERS  ERS  RST  RST  DPE  2SC                 ABS  ABS  ABS  ABS  ABS  ABS  ABS     __________________________________________________________________________     TOTAL SUM            1    2.9  4.1  8.0  5.3  4.0  98.7 5.3            2    2.5  3.9  8.5  4.5  4.0  98.6 6.9            LOCS 2    7    1    2    3    3    9            REPS 6    9    2    3    5    3    9            DIFF 0.4  0.2  0.5  0.8  0.0  0.1  1.6            PR > T                 .205 .855      .205 .999 .967 .003#     __________________________________________________________________________      * = 10% SIG      + = 5% SIG      # 1% SIG

Deposits

Applicants have made a deposit of at least 2500 seeds of Inbred Maize Line PH03D with the American Type Culture Collection (ATCC), Manassas, Va. 20110 USA, ATCC Deposit No. 209796. The seeds deposited with the ATCC on Apr. 20, 1998 were taken from the deposit maintained by Pioneer Hi-Bred International, Inc., 700 Capital Square, 400 Locust Street, Des Moines, Iowa 50309-2340 since prior to the filing date of this application. This deposit of the Inbred Maize Line PH03D will be maintained in the ATCC depository, which is a public depository, for a period of 30 years, or 5 years after the most recent request, or for the effective life of the patent, whichever is longer, and will be replaced if it becomes nonviable during that period. Additionally, Applicants have satisfied all the requirements of 37 C.F.R. §§1.801-1.809, including providing an indication of the viability of the sample. Applicants impose no restrictions on the availability of the deposited material from the ATCC; however, Applicants have no authority to waive any restrictions imposed by law on the transfer of biological material or its transportation in commerce. Applicants do not waive any infringement of their rights granted under this patent or under the Plant Variety Protection Act (7 USC 2321 et seq.). U.S. Plant Variety Protection of PH03D has been applied for under Application No. 9700208.

The foregoing invention has been described in detail by way of illustration and example for purposes of clarity and understanding. However, it will be obvious that certain changes and modifications such as single gene modifications and mutations, somoclonal variants, variant individuals selected from large populations of the plants of the instant inbred and the like may be practiced within the scope of the invention, as limited only by the scope of the appended claims. 

What is claimed is:
 1. Seed of maize inbred line designated PH03D, representative samples having been deposited under ATCC Accession No.
 209796. 2. A maize plant, or parts thereof, having all the physiological and morphological characteristics of inbred line PH03D, representative seed of said line having been deposited under ATCC accession No.
 209796. 3. The maize plant of claim 2, wherein said plant is male sterile.
 4. A tissue culture of regenerable cells of a maize plant of inbred line PH03D, wherein the tissue regenerates plants capable of expressing all the morphological and physiological characteristics of the inbred line PH03D, representative seed of which have been deposited under ATCC Accession No.
 209796. 5. A tissue culture according to claim 4, the cells or protoplasts being from a tissue selected from the group consisting of leaves, pollen, embryos, roots, root tips, anthers, silks, flowers, kernels, ears, cobs, husks, and stalks.
 6. A maize plant regenerated from the tissue culture of claim 4, said plant capable of expressing all the morphological and physiological characteristics of inbred line PH03D, representative seed of which have been deposited under ATCC Accession No.
 209796. 7. A method for producing a first generation (F₁) hybrid maize seed comprising crossing the plant of claim 2 with a different inbred parent maize plant and harvesting the resultant first generation (F₁) hybrid maize seed.
 8. The method of claim 7 wherein inbred maize plant of claim 2 is the female or male parent.
 9. An F₁ hybrid seed produced by crossing the inbred maize plant according to claim 2 with another, different maize plant.
 10. An F₁ hybrid plant, or parts thereof, grown from the seed of claim
 9. 11. A process for producing inbred PH03D comprising:planting a collection of seed comprising seed of a hybrid, one of whose parents is Inbred PH03D said collection also comprising seed of said inbred; growing plants from said collection of seed; identifying said inbred plants; selecting said inbred plant; and controlling pollination in a manner which preserves the homozygosity of said inbred plant.
 12. The process of claim 11 wherein said step of identifying said inbred plant comprises:identifying plants with decreased vigor.
 13. The process of claim 11 wherein said step of identifying said inbred plant comprises:identifying seeds or plants with homozygous genotype. 